Train-control system



April 1 1924.

TRAIN CONTROL SYSTEM y 7/ Filed Jan. 11. 191'? s sheets-sheet 1` 7/ f@/7/ .--1 l "".L fgz., $9 @@I In I 'J I n J 'g I -n J 7l 7( 7 JZ 114 @c iv HZ 8'/ QZ L ac i 9J V... f\ 'r l I l 2 x-I NJ gli y J, )i *Y 5 5 f IN V EN TOR.

April 1 1924.

1,488,469 E. J. BLAKE TRAIN CONTROL SYSTEM Filed Jan. Y11, 1917 3 Sheets-Sheet 2 Ej-5:1 2. F23 5.

April 1 1924. 1,488,469

E. J. BLAKE TRAIN CONTROL SYSTEM Filed Jan. vll 1917 3 Sheets-Sheet 3 /f t: 1. E I I 5\ g 7 I n 24 6` 7&1 104 ZZ/ j Patented Apr. 1., 1924.

UNITED s'rilritsl `Parri-:rrr OFFICE.

ELI J. BLAKE, F WISTFIELD, NEW JERSEY, ASSIGNOR T0 HALL SWITCH 4SIGNAL C0., A CORPORATION 0F MAINE TRAIN-CONTROL SYSTEK.

Application filed January 11, 1917. Serial No. 141,816.

T0 all whom it may concern: l

Be 1t known that l. Em J. BLAKE, a citizen of the llnited States. and a resident of the town of 'estfield, county of Union, and 6 State of New Jersey. have invented certain new and useful Improvements in Train-Control Systems, otl which the following is a specification.

It has heretofore been customary to locate roadside signals at intervals not less than the braking distance of the fastest trains. stop signal has been displayed at the entrance to each occupied block, a caution signal at the entrance to the next block in the rear and a proceed signal at the entrance to the second block in the rear. Between each train and the next proceed indication in the rear there has thus been maintained a distance composed of: fi1'st,`tlie distance between the train and the entrance to the block which it occupies; second. the distance between the stop signal and the caution signal. which must not be less than the maximum distance required to stop a train; and, third, the distance between the caution signal and the next signal in the rear. Of these three distances only the second is dictated by safety; the first and third are due to the spacing of signals along the roadway.

In order to reduce the interval between trains, and thereby increase the traffic capacity of the railway, the length of blocks has sometimes been made only half of the maximum A braking distance. Two distinctive caution signals have then been displayed in the rear of the entrance to the occupied block. so that the total length of the second. or caution zone, remains the same as in the first instance; but the length of is the well known system-of block signaling with one block overlap.

It is evident that further subdivision, of the blocks with multiple blocks overlap would permit the first and third zones to be made very small so that the headway between-trains operating on proceed, or'full speed. signals could closely approach the minimum distance dictated by safety, which is the maximum distance required for stopping the following train. Furthermore, by the use of distinctive caution signals, indicating the number of clear blocks between each signal and the occupied block, operation' at restricted speeds could be permitted the first and third zones is reduced. This line wires extending through the control zones of the signals, and thereby to permit of safely operating trains at reduced headother object is to reduce the number of signals required for overlapping control, and at the saine time to insurethe visibility of signals under all conditions, by substituting cab signals for roadside signals.

Another object is to provide means for automatically controlling the train in accordance with the indications of the signals if the engineman fails to do so; which means will not act so long as the engineman is governed by the signals.

Another object of my invention is to provide on the train continuous indications of the condition of the track in advance. which indication will he predisposed to indicate danger, every safety indication being dependent on the integrity of track circuits and all other parts of the system in accordance with the best signaling practice.

Another object is to provide for safely operating trains at various speeds, the minimum headway between trains being dependent on the speed of the following train, and approximating the distance required to bring it to rest from the speed at which it is moving.

Another object is to permit the movement of the maximum possible traic over the railroad without permitting any train 'to approach a dangerous point at a speed which would prevent stopping short of the danger point.

Another object is to provide controlling apparatus and circuits which will attain the ends that have been enumerated with minimum of apparatus and of conductors.

Another object is to provide means on the train whereby its operation under given of 1)frequency indi in piace of color shows a modification of the .o 1 system arranged to control a roauside signal M23 instead of a signal on the. train. Y

v,. ligure- 5 sli-Orts modification of the system.

`Tigures 6 to l0 inclusive show modigcations of the apparatus carried 'the train for controlling it.

Figure 1l shows a timing device hy which unler certain conditions the speed of the 'train he limited.

Figure l2 shows a relay design-ed to close one of several circuits selectively in accordance with the frequency by which the relay is energized.

referring i'irst to Figure l. l and 2 are the rails of one railway track, divided hy insulated joints 3 in the block sections (L, l), c, 659 e. e, 5 and 6 are three conductors entending1 along the track. Between each tivo of these conductors is maintained by any suitable means, an alternating difference of potential. From conductor fl to conductor 5 this potential has one frequency, and from conductor 5 to conductor G another frequenc f; and from conductor 6 to conductor l a third frequency. Connected in shunt across the lines 4, 5 and G near the entrance end of the block a are connected the primary windings of the three transformers 7b, 8b and 9b, each energized at a different frequency. r@ne secondary terminal of each transformer is connected to the rail l near the exit end of the block section 3. rEhe other terminal of one or another of the three transformers is connected selectively to a corresponding -point in the rail 2 through a relay cont-act 10a. lhe selection of contact points in this relay is determined loy the frequency of current supplied to its operating Winding llLL or the absence of such current, as hereafter described. The Winding 1l:l receives its energy as shown from the rails at the rear end of 1block a. Similar apparatus and connections are employed at the corresponding point of each lolocli section. rhus there will he supplied to block sectiea its e `it end a eurthe lines l and il. .he relay if end rf this block (which unocis therefor-,eJT energized at the same y, with the result that the contact 1Gb is raised to the position shown and the following' hlocl; c is supplied Vwith energy of J"efuency cf the lines 1land 5. The ,seing also unoccupied the relay llc is supplied with energy at the frequency with the resuit that c ntact 3 0@ assumes the position indienergy of the frequency of fiori into the bloeit (Z. mhe il at the r i end the at the frenuency c l angcd tlc-lr E is energized the lines 57 6. rEhe Contact .dfi

to assume at this frequency., 'the sani-e position which it assumes at the frequency of ne iines so that same i cpiency is l' to the block e in the rear7 and in e manner to succeeding,A blocks.

l thus be seen that energy is supplice to successive clear loloclr sections in follows:-

the first hiocli atthe ileduency of :ie lines a, G; to the second hloci; at the all succeeding unoccupied blocks at the frequency of the lines 5` G. .Evidently there has thus been provided a distinctive indication in each block of the numher of clear blocks in'advance up to two hioclis which indications can he received hy an)v device capable of responding selectivel)v to the three frequencies in question. For example lf have indicated at. lil in the block e a pair of wheels and an axle constitutingY the primary winding' of a transformer lcarried by a following train. From the secondary Winding of this transformer current is taken to an amplifying device l5 which also receives energy from a battery 1G. any known h ll llO

type of amplifier may lic usedv` for example The current from the lamps Gr Y or R if any, passes also through a. speed controlling device 18 and thencev through amagnet 19 controlling the application of the brakes on the train, or through a wire 20 as the case may be, to the batteryl 16. The speed con trolling device 18 which may consist ot one or more devices as shown in Figure 11, or any other suitable speed ycontrol device is so arranged as to close the circuit through magnet 19 when the speed ,of the train is within the limits permissible under the indication received from the track corresponding respectively to the lamp G Y or R; but to complete this circuit through vthe wire 2O without passing through the magnet 19 whenever the speed, exceeds the value permissible under the given conditions. That is fto say, contact 27G-3GG is closed at all speeds at and below a given high value,

'and at speeds exceeding such value this contact opens andl contact 27G-2OG closes, so

that when the circuit through lamp G is Y closed at contact 17, brake magnet 19 is enel'- gized when the Speed is at `or below the given high value and de-energized when the speed exceeds such given high value. Similarly, cont-act QTY-36"y is closed at all speeds at and below a given-` intermediate value,

whereas at speeds exceeding such value thiscontactcpens and contact 27Y-20Y closes. so that when'the circuitl through' lamp Yfvis closed at Contact 17, brake magnet 19 is energized 'or de-energized according as the speed' is below or above such intermediate value. Also, contact 27R-36R-is closed at all speeds at and below a given low value,

whereas at speeds exceeding such value thisu contact `1s openv and contact 27E-20R 1s closed, so 'that when the `circuit through lamp R is closed at contact 17,y brake magnet -19 is energized orv tie-energized accordy ing as the speed is below or above such given low value. Each group of contacts 27-36-30 may be'controlled bv a. device i similar tov that shown in Fig. 11 described hereinafter. The magnet 19 controls a valve arranged to set the brakes when the magnet is de-energized.

In Figure 1 it is evident that in addition to the direct path through the generator connected directly to`4 any given pair ot conductors thereis a. second path through the other two generators in series. In order to I' avoid short Vcircuiting of one armatureby Y the path through the other two armatures and also in order'yto avoid4 thev suipply to any given pair of conductors of any considerable current other than that of the ;\1-. ternator directly connected across them. each- .alternator or its circuit. should have the characteristic of permitting freely the flow system.

Referring now to Figure 5, in this figure I show circuits similar to those of Figure 1 with then following exceptions: The insulated joints which separate the track rails between adjacent block sections are bridged by inductive ybonds21 of the well known balanced type, for the purpose of carrying the return current of an electric traction The same circuit is used asa common return for the circuits of the three alternators 22, Z3 and Q4, while each of the conductors 4, 5 and 6 is connecte-d only to one alternator. In instance the three frequencies are obtained by the use of one conductor for each frequency inA addition to the common return path through the rails connection to the latter path is made at the neutral point -oft the balanced bonds.

lVhile I have shown' in Figures 1 and 5 arrangements for the` use of only three fre'- quencies for controlling traiic over a corresponding number of blocks in the rear of each occupied block, it is evident thatl the same principles can be applied with the use of any number of frequencies to control traffic over any number of blocks in the rear of the occupied block,A and although I have shown only two types of track circuits, the same principles can be applied with any type of track circuit which will permit the en` ergy supply to one block to be made dependant on the energy supplied to the next block in advance. It is also evident that the indications given by the selection of the frequencies may be used for other purposes than the indication of clear blocks ahead as for example, for indicating routes through interlocking plants. Y

In Figure 4 I have shown another form of my invention in which supply of current to the various blocks is identical with that shown in Figure 1,'but the current is used to select the indication 'Y given by roadside signal 25. In this instance the relay has in addition to thecontact arm 10a,-"etc., ref quired vfor supplying'current to the block in the rear a second contact arm 26a, etc., moving in the same manner as the arm 10a, etc., but employed to supply current selectively to one or another lamp ot the light signal 25.

Figures 6, 7, 8, 9, and 10 show various arrangements of apparatus on the train which may be used in place of the lamps and speed control device shown in Figure 1. -In each ca se the devices' shown are controlled by the current delivered by the amplifier 15 yin Figure 1. .A

In Figure 6 I have shown an arrangement of relay-controlled circuits, on the train by means of which one or another` of three sigvnal lamps G Y and-R, is illuminated, ac-

cording to the number of clear blocks in advance of the train.

In Figure 2 I have shown in place of the relay and lamps of Figure 6 a frequency indicator of the type in which a pointer swings across a scale as the frequency rises. But

' instead of graduation indicating frequency supplied to the meter I lhave shown graduation indicating for each frequency the number of clear blacksiahead.

In Figure' 7 I have shown the same circuit as in Figure 6 with the addition of a magnet 19 for controlling application of the brakes and a speed control device 27 such as shown in Figure 11, having the characteristics of opening an electrical circuit when the speed exceeds a certain value. The speed at which the circuit through the speed control device 27 will open is determined by the distance traveled by the train in such a manner as to bring the train to rest substantially at the exit end of the block in which this circuit was first energized irrespective of the speed at which the train entered the block. It will be evident by examination of Figure 7 that as long vas the lamp G is energized, indicating three clear blocks in advance of the train, the magnet 19 will be energized. This magnet is associated with the air brake system in such a manner that releasing the magnet will cause the brakes to be applied. Upon entering the Asecond clear block in the rear of an occupied block the frequency supplied to the train will be changed to that fed to the second clear block in the rear and the contact arm 17 will dropvv to the position in which the'battery circuit is closed through the lamp Y the speed control device 27, and

the magnet 19,. The magnet 19will now ref main energized as long as the train does not exceed #at any point thev maximum speed which will permitl of its'beingstopped at the exitl end ofthe block in which it is traveling. On reaching thefirst clear block in the rear of the occupied block the contact arm 17 will close the circuit through the lamp R and open the circuit through the magnet 19, causing the' train to stop immediately. l" i In Fig. 8 I have shown circuits controlled by a relay operating in four ositions, eacl1 corresponding to a particulilr fre uency and a corresponding number of clear locks in advance of the-train, and a fifth position corresponding to absence of energy. In this in advance of the train. A first caution-in-` dication is given by the lamp Y three blocks in the rear of the occupied block. As lon as current flows through either the lamp or the lamp Y the magnet 19 remains energized, but upon entering the second clear block, in. the rear of the` occupied block conf tact 17 is closed through the lamp B, the

contact 27b and the ma net 19, the contact 27b as described hereater is arran ed to open whenever the train exceeds a enite speed limit. Similarly the circuit throu h the lamp R is closed through the contact 2 corresponding to a lower speed limit, and the magnet 19. As the train approaches an occupied block, it receives first a yellow light warning the engineer to reduce his speed to the limit corresponding to the contact 27". Should he fail to do so the brakes will automatically be ap lied at the entrance of the second clear bloc in the rear of the occupied block. At the same point, irre-y spective of speed, the lamp B is lit, indicating that speed must be reduced before entering the next block to the value corresponding to the contact 27. The latter contact is adjusted for a low speed at which it is permissible to operate the train all the way to the entrance of the occupied block; but upon reaching the latter point the relay contact arm 17 will open the circuit of the magnet 19 and cause the automatic application of the brakes.

In Figure 9 I have shown an arrangement similar to Figure 8, with the exception that the speed which will cause an automatic apy R speed limiting` devices similar to 27 in Figure 7. `In each case the speed limit device 27 is adjusted to enforce a speed limit varying between the ermissible limits at the entrance and exit en s of the block.

In Figure 10 I have shown an arrangement similar to Figure 7 except that two yspeed control devices 27H and 27L are here employed in place ofthe single device 27 in Figure 7. However, only one of these devices acts `at any given location. The train is controlled by track circuits of three frequencies in the rear of the occupied block as in the case of Figure 7; but at different locations two different frequencies are supplied tothe second clear block in the rear of the occupied block;

lone frequency adapted to select the speed conmay be employed on level tracks` and thesecond on down grades, and the control devices 26H and 26IJ may be adjusted for corresponding braking curves. Similarly speed control in accordance with one of any num-L ber of braking curves can be selected by the use of suitable controlling devices, responsive todifl'erent frequencies.

In Figure 11- I have shown one form of speedcontrolled contact device suitable for enforcing a constant speed limit. A cam 30 is mounted o n a shaft 31, which is driven, by

gearing or otherwise, at a speed proportioned to the speed of an axle of a train. Resting upon the cam 30 is a roller 32 carried by a heavy arm 33, loosely mounted at 34 on the extended shaft of a clock or other timing mechanism 35. The timing mechanism is so arranged that the shaft 34 may be turned counter clockwise against the torsion of the mainspring without other restriction; but clockwise movement is limited to a definite maximum rate. Rigidly attached to the shaft 34 is a sector ratchet 29 carrying an insulated arm 28. The latter arm is arranged under normal running conditions to move upward with each revolution of cam 30 almost into engagement with the contact finger 27 which rests upon a fixed contact member 36 and closes a control circuit` between the wires 37 and 38. A pawl 39 on the arm 33 normally engages the second notch 40 of the sector ratchet 29 as indicated. As long as the permissible speed of the train is not exceeded the arm 33 oscillates in unison with the ratchet 29 during each revolution of the cam 30, carrying the ratchet 29 and the arm F28 to the position indicated, wit-hout opend ing the contact between the parts 27 and 36.

During t-he following revolution, the arm 33 graduall rises to its highest position and the arm 28 'rops away from the contact finger 27. The sector ratchet 29 Xcontinues to en gage the pawl 39, at second notch. However, should the speed of the train be such that the upward movement of the arm 33 is more 'rapid than the maximum speed at which the timing mechanism 35 will permit the sect-or ratchet 29 to revolve, then the arm 33 will carry the pawl 39 to the first notch 4l of the sector ratchet 29. -The succeeding downward movement of the arm 33 will raise the arm 2.8 to the position shown in broken lines and cause the contact between the fingers 27 and 36 to be broken. At the same time a pawl 42 pivoted on the case of the timing mechanism 35 will engage the third tooth 43 of the sector ratcheta 29, causing lthe contacts 27 and 36 to remain open until the pawl 42 has A been released.

on which the governor 47 is carried, through a small distance. At another and higher speed the weights of governor 47 will fly out raising the sleeve 49. The tip of the sleeve 49 may thus occupy three different positions, the lowest when the speed is insufficient to throw out either of the governors 46 and 47; the intermediate position when 46 yis thrown out and 47 is not thrown out; and

the highest position when both are thrown out. Resting upon the tip of the sleeve 49 is a plate 50 attached to and insulated at 51 from the contact arm 52. The latter through a spring contact tip 53 closes the circuit between the wire 54 and the wires 55, 56 and 57, according as the sleeve .49 occupies one or another of the positions which have been described, hence according as the motor 44 is energized by current of one or another frequency.

In ligurev 3 I have shown symbolically an arrangement of two relays of the well known frequency selective type, one relay 58 arranged to close only when the frequency supplied to it is less than a certa-in value, the other relay -59 arranged to close only when the frequency supplied to it exceeds another and higher value. It is evident from inspection that the circuit from the wire 54 to the wires 55, 56 and 57 will here be made selectively as in the case of the matic block signaling practice, it is evident that the same principles can be applied for giving indications of any desired conditions, asin the case of interlocking signals.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A railway signaling system comprising a trackway; means for dividing the trackway into signaling sections; means for supplying toeach signaling section a plurahty of alternating current potentials of different frequencies; devices associated with each signaling section for controlling the frequency to be supplied to the adjacent section and controlled as to its operation by the passage of a vehicle along the tracltway; a vehicle for travel along the railway; a circuit on the vehicle arranged to receive energy from the alternating potential of the signaling section on which it may be located; an amplifying means on the vehicle and '1neluded in said circuit; an electricallyfoperated device which is selectively controlled by the operation of the amplifying means; and a plurality. of governing means on the vehicle which are selectively controlled by said electrically operated device` e tiaclivvay; inesis Way into signaling sec io @lying to eacli signaling of alternating ciii'ie is potentiels Gf iequencies; devices associates vv' signaling section for controlling qnencg7 to be supplied to the seis, tion and coniolled as to Yits opera cuit on lie vehicle eii'sngecl to ieee/ive energy from the alternating poieniai ci un amplifying means on i'lie vehicle and ilicluclecl in seid circuit; en eleciicmly ooe?- afe. device which is selectivel",v confollecl signaling section on which it may be locates.

by the opeiation of the amplifying means; zzn-5. s plurality of signals on the velncle which are selectively contiolleci my sail elecicelly Operated dev'ce'.

3. A railway signaling system comprising a i'ackvvey; means for clivicling the reci? 'any into signaling sections; niesns for sin Diving to eacli signaling sec-ion s. plnizzlii'y alernating cuiient potentials of clieiens iiecuencies; devices essociaecl with escl-i signaling section foi coni-soiling' the 3- quencgf to loe snppiiecl o the adjacent section snc?. confollefl as "fo its oneieicn by the passage of e. Vehicle f vehicle foi im'el cicui; en the i enegy fcin ille aleinsing poen ici cf meng the sions; e,

signaling section on which is e lo Jeil; en finiplifying mens on "l" l included in sei@` circuit; s eieeci device vvli' i sei collecw by the 09el ns; signals on iectiveljv coniollee` avec. device; and net in ciicu vvif'cli ene o1' sessi 'm luv/ay ino signelin @iisg ienne ssage of e vehicle ale-n l lcle fol iflecl cioi device ii ciicui; vrili anotliei' ci se 'u' signals and ssii?. brile fiontioliing inn;V iet.

L rail i e" system comprismy signziiin ing e. tiaclwzy; ine-sns foi' dividing the iaclmvey inuo signaling secions; ineens for supplying to escli signziline' section :i plu- 'Ljy of ci l'ient pcenliiels of clilliei'ent cyclic variations; devices zissocie'ecl iviili ezicli signaling; secticn 'for conil'f lling Clie cinient to be suppliceL so die adjacent section and conidlecl es to iis @pei-alien by the passage of s. vehicle along -lie iieciiivey; e vehicle for along the "iecli'vvsjv; e circuit n the vehicle ziilaped ic 'receive energy fion'i die signaling section on which the vehicle may be locsecl, and spee l ccntiol appeinus on ille vehicle selectively responsive to the elecl'iic cui-rents of clileient cyclic yzuifiions5 final including' one iiienibei' moving at conslzin speeil zinc, :incliei niembe: coacting therewith and nicv" e' et speed dependent upon ille speed ille "i 6. A railway siffnelingg system can; ing e trackvvay; l

ineens foi' iliviei'eg taclvvziy inici signaling sections: ineens 10i'.

sugplying o each sig ion e1 le en r e veel l'i'oin ,ci @ne el" nier-e. circuits on railway; a circuit on the vehicle arranged to recelve energy from the alternating potential of the signaling section on whichl it may be located; an electrically operated device selectively controlled according to the frequency Aof the potential supplied to said circuit; and an amplifying means interposed between said circuit and said device.

9. A railway signaling system comprising a trackway, means for dividing the trackway into signaling sections; means for supplying to each -signaling section a plurality of current potentials of different cyclic variations; devices associated with each signaling section for controlling the current to be supplied to the adjacent sectionand controlled asvto its operation by the passage of a vehicle along the trackway; a vehicle for travel'along the trackway; a circuit on the vehicle adapted to receive energy from the signaling section on which the vehicle may be located; arnplifying means in said circuit, and apparatus selectively responsive to the electric. currents having different cyclic variatlons.

10. Railway traffic controlling apparatus comprising a. series of track sections, means for each section for connecting a source of alternating current of one frequency or an,- other across the rails of the section at the exit end of the section according to traflic conditions in advance of the section, a circuit on a train receiving voltage from the track rails by induction, governing means on the train controlled by the volt-age induced in `said circuit and including--means selectively responsive to currents of the. frequencies supplied to the track rails, and amplifying apparatus between said receiving circuit and saidselectively responsive means.

11. In a system of signaling,` a series of successive block sections, means for supplyingsaid block sections with current of one or another frequency for the control of signals, and means whereby the frequency supplied to each section determines lthe frequency supplied to the next section in p the rear.

12/A train`control system comprising a section of track, means for selectively supplying electric power to said track at one or another frequency, a train on said track, a circuit on said train receiving energy from said track, amplifying meanslvin said circuit, l,and means selectively responsive to the frequency in said circuit to control apparatus on the train. 13.A train,I control system icomprising section'of\ tracka plurality of line wires supplied with energy of different frequencies, a pluralityof transformers bridged across said line wires, means for selectively energiaing said track from one or another of saidtransformers, a train on said track, a circuit on said train receiving energy trom said track, and means selectively responsive to the frequency in said circuit to control apparatus on the train.

14. Railway traflic controlling apparatus comprising al trackway divided into sections, means for each section for supplying alternating current to the rails thereof of one frequency or another, a vehicle, vehicle carried means controlled by energy received from the track rails and selectively responsive to currents ot' the several frequencies supplied to the rails, and vehicle governing apparatus controlled bysaid vehicle carried means and requiringl the control of said vehicle carried means by current in the track rails yto allow the vehicle to proceed at maximum speed.

cle carried means controlled by energy received from the track rails and selectivelyY responsive to currents of said different frequencies, and vehicle governing apparatus controlled by said vehicle carried means and requiring control of the vehicle carried means by current of a certain frequency in the track rails to allow the vehicle to proceed at maximum speed.

16. Railway trafiic controlling apparatus comprising track rails, a vehicle, meanson the vehicle for .permitting the vehicle to proceed at maximum speed and other means on the vehicle for permitting the vehicle to proceed at restricted speed, apparatus on the vehicle controlled by energy received from the track rails and selectively responsive to current of one frequency or another for rendering one or the other ot said vehicle-carried means effective, and means for supplying current of one of said frequencies or the other to the track rails.

17. The method of controlling traffic'. which consists in. producing an alternating disturbance along a trackway carrying traflic to be controlled, governing the frequency of said disturbance by trafiic conditions in advance, producing by said disllt) trolled, producing by said disturbance a. corresponding electrical disturbance in a vehicle to he controlled, influencing` thereby a localsource of energy to pro-duce energY changes et a corresponding relatiye iire duency to the disturbances and greater than could. lie directly derived from the disturbance, and causing said local energy changes to selectively actuate tratlic controlling;` means. i

l). rhc metnol or controlling trafic, which consists producing an alternating disturlmnce along a traclru'ay carrying traliic to be controlled, goyeiniine the frequency or said disturbance by tr-aille conditions in advance, producing by said disturbance an alternatingelectromotiyc Yforce ot' corresponding` lirequency in a Vehicle to be controllei'l, controlling thereby a local source ot' direct currentto produce an alternating currentoi' a. correspon( inp relatiye- 'fre quency, but regeneratiyely amplified, and actuatingtraiiic controlling means on said vehicle by, and in accordance With the 'irs quency of, said amplified current to control the train in accordance with traiiic conditions in advance.

2li. llailn'ay '-"raiiie controlling' aA pa atus comprising raclzu'ay divided bloeir sections and a vvehicle .for tray circuit on said Vehicle, a plurali y sources of alternating' current ot dii'ferent frequencies associated with each traclr section, means associated with each traclr section and controlled by t atie conditions in ac Yance selectively inipressino one of said *frequencies to the tracl; section for creating an alternating' electromotiye force of corresponding' `iequency in said vehicle carried circuit, a second circuit on said vehicle including a local source o'f current, amplityiij means controlled hy the, alternating electroniotiye torce in said first: circuit for causing Tarief lions in the current in said second circuit of a correspondir eiatiye frequency, and yeliicle Agoverning' means controlled by the jredueney oi the currentyariations in the second circuit.

2l. ailn'ay tradic controlling apparafus comprising a traclmay and a. vehicle r trarel thereon. circuit on said vehicle, means 'tipi' imgressing upon the traclrway alteratingcl elecrromotiye force of one or another predetermined frequency whereby a coresponding frequency is induced in said circuit. a second circuit on said Vehicle including a source' of current, amplifying means on the vehicle responsive to the induced frequency in said i'lrst circuit for causing variations in the flow of current in the second circuit of a corresponding rela.- tiye frequency. and vehicle governing means controlled by the Jfrequency of the Varia-tions in the current in said second circuit.

:22. i railway system embodying means Jfor producing a clearance current for unlimited speed. and a. different current. for limited speed, means biased to retard the train and thrown out ol operation by said clearance current, and means for producing a limited speed responsive to said` limited speed current.

23. i railway signaling system comprising a plurality of track sections, a relay l'or each section receiving energy from the rails the section and comprising a member rotatable at two diii'lerent speeds according;Y as the relay is energized by alternating current ci' one frequency or another, said relay also comprising; a plurality oll contacts one or another orf which is closed according as said member rotates at one speed or the other, means controlled by the relay of e: ch sec tion 'for supplying current or one of said frequencies or the other to the rails oi the section in the rear, and signals for tl sections controlled by the said relay contee" 2l. il railway signaling system comprising a plurality of track sections, a relay 'for each section comprisinga motor receivingi energy from the rails of the section e l ro tatable at one speed or another accorc n it is energized by alternatingeuii'erty ol one dfrequency or anotherpeach relay also comprising a speed responsive device operated by the motor and a plurality of contacts one or another ot which is closed according; as the speed responsive device is operated at one speed or the other, means contro the relay oi1 each section for supplu O rent oi one oi said frequencies or the other to the rails of the section in the ri, signals the sections controlled said relay contacts.

signaling` system comprising4 a pi rality of traclr sections, a relay for ach sec tion comprisingl a motor receiving;`

from the tracl: rails of the section and erahle at diiilerent speeds according its it is energized by current oi one requency or another.. means controlled by the relay of each section lor supplying current o'f one ot said frequencies to the rails olf 'he section in the rear when the relay is cre-ener- `e'ized and for supplyingr current ol the other said `frequency to said rails when relay is energized by current orl either frequency, and a signal controlled by each relay and indicating` stop when the motor de energizedy caution when the motor operates at one of said speeds, and proceed7 when the motor operates at the other speed.

2G. A signaling system comprising a plurality ot track sections, a relay for each section comprising a motor receiving,- energy Yfrom the track rails olf the section and rotatable at ditlerent speeds according to the itrequency of the current by Which it is enerlllzi lll) gazed, each relay also comprising a centringe, operated by the motor, means controlled by the relay of each section for supplying current of one frequency or another to the rails of the section in4 the rear and a signal controlled by eacli relay and indicating stopy when the centrifuge is at rest., caution when the centrifuge operates at one speed, and proceed When the centri-v fuge operates at another speed.

27. Railway traffic controlling apparatus comprising a series of track sections, means for each section for connecting a source of alternating current of one frequency or an other across the rails of the section at the exit Aend of the section according toy traffic conditions in advance of the section, and train carried governing apparatus controlled by energy received from the track rails and including means selectively responsive to 'the frequency of the energy in said rails. Y

l28. Railway trafic controlling apparatus v comprising a series of track sections, means for each section for connecting a source of alternating curi-ent of one frequency or another across the rails of the section at the exit end of the section according to traiiic conditions in advance of the section, a circuit on a train receiving voltage from the track rails by induction, governing means on the train controlled by the voltage induced in said circuit and including means selectively responsive to currents of the frequencies supplied to the track rails.

'In testimony whereof, I have signed my lname to this specification.

ELI J. BLAKE. 

